The sound motion-picture camera, in conjunction with the cathode-ray oscilloscope using internal individual muscle electrodes, represents an excellent and practical method for recording the phasic activity of the muscles of the lower extremity. The importance of phasic activity in the normal and the preoperative and postoperative paralytic patient is demonstrated. Phasic transfers in general retain their preoperative phasic activity. They also appear to regain their preoperative duration of contraction and electrical intensity. Many non-phasic transfers retain their preoperative pattern of phasic activity, failing to assume the desired action of the muscle for which they are substituted. Certain non-phasic transfers are capable of phasic conversion.